Cyl - Compression
1. 30
2. 110
3. 40
4. 0
5. 115
6. 110
7. 160
8. 0

was running fine a few days ago...then just died...
Tensioners replaced 18 months ago. Chains feel tight.
Head gaskets???

 

How many kilometres/miles are on the vehicle?

What DTCs are stored?

Has the engine been overheated?

Does the engine rotate freely in a clock direction when viewed from the front with the spark plugs removed?

Are the camshafts in proper phase with the flats facing the same way?

 

The attached PDF shows the cylinder numbering sequence for the X308 up to 2004. Cylinders 4 and 8 at the back of each cylinder head should be checked with a bore scope, or a leak test performed to determine the cause of lost compression. This should also include cylinder 1, which has very low compression.

 

156000 miles
has not overheated
Engine turns over freely while doing compression check.
haven't checked if cam "flats" are aligned...not sure what that looks like.
I'm an old school Chevy guy.....this is my 1st Jag.

 

Ehull, when you turn the engine over, do you hear hear any clanging engine components? As NBCat provided the pdf file, the second and third pictures down from the top is the cylinder ID that you need. Seeing those numbers you provided makes me think that engine was running so hot that valve seats dropped in cylinders 1,3,4 & 8. Is it possible that you didn’t hear any fans running on high and it just shut off? I know you said it wasn’t running hot but, I can’t imagine blown head gaskets showing those particular cylinders especially in 1 & 8 by themselves. How does the oil level and condition look like? Same for the coolant in the expansion tank?

 

Coolant level was a little low but visible. Oil level about 1/2 quart low...looked normal. No noise while cranking over during compression test. When problem 1st occurred, was able to start after disconnecting MAF sensor but with very rough idle that smoothed a little above 2000rpm. Did not let it keep running like that.

 

rearrange the data in “alternate” cylinder numbering

i’ve heard of phasers going out and killing compression on one bank before. the flats will be visible when you turn it over

 

Flooded? Some of these cars flood if started cold, then shut off after a minute.
If so, some folks floor the gas pedal, which shuts off injectors, and crank for 30 seconds or so, then try to start with 1/4 throttle.
Or, remove plugs, squirt oil in cylinders, maybe crank over a little with the pedal floored, to make sure there's not too much oil in a cylinder. Then, new plugs, or cleaned plugs and start.
Rob